Publication: Reduction in anisotropic response of corrosion properties of selective laser melted Co–Cr–Mo alloys by post-heat treatment
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Issued Date
2020
Resource Type
File Type
application/pdf
ISSN
1095641
Other identifier(s)
2-s2.0-85096199148
Rights Holder(s)
Scopus
Bibliographic Citation
Dental Materials. (2020)
Suggested Citation
Kajima Y., Takaichi A., Kittikundecha N., Htat H.L., Cho H.H.W., Tsutsumi Y., Hanawa T., Wakabayashi N., Yoneyama T. Reduction in anisotropic response of corrosion properties of selective laser melted Co–Cr–Mo alloys by post-heat treatment. Dental Materials. (2020). doi:10.1016/j.dental.2020.10.020 Retrieved from: https://hdl.handle.net/20.500.14740/4949
Abstract
Objectives: The application of selective laser melting (SLM) to dentistry has been rapidly expanding; however, SLM-processed parts possess orientation-dependent properties (i.e., anisotropy) that can affect the long-term reliability of the dental prostheses. This study aimed to evaluate the anisotropic corrosion response of SLM-processed Co–Cr–Mo alloys under various heat treatments. Methods: Samples fabricated via SLM along the horizontal plane (x-y plane) and vertical plane (x-z plane), with respect to the build direction, were subjected to various heat treatments. The resulting microstructures of the samples were characterized, and their corrosion properties were evaluated using anodic polarization and immersion tests. Results: All samples showed similar transpassive behavior of the polarization curves. However, the immersion tests showed that the as-built x-z plane samples released significantly more metal ions than those fabricated on the x-y plane because of the larger area of preferentially corroded molten pool boundaries (MPBs) in the x-z plane samples. Our results further demonstrated that the heat treatments eliminated the MPBs, resulting in isotropic corrosion properties. However, excessive heat treatment at high temperatures induces the formation of coarse precipitates, resulting in a less-protective passive film. Significance: The post-build heat treatments at temperatures that eliminate the MPBs are effective in reducing anisotropic corrosion behavior, and the lowest possible temperature is suitable for reducing the amount of released metal ions. These findings are expected to facilitate the application of SLM in dentistry to allow fast and precise production of prosthetic devices. © 2020 The Academy of Dental Materials
Subject(s)
Anisotropy
Corrosive effects
Dental prostheses
Dentistry
Heat treatment
Metal ions
Metals
Molybdenum alloys
Polarization
Prosthetics
Anisotropic response
Corrosion behavior
Corrosion property
Orientation dependent
Polarization curves
Post heat-treatment
Prosthetic devices
Selective laser melting (SLM)
Selective laser melting
Corrosive effects
Dental prostheses
Dentistry
Heat treatment
Metal ions
Metals
Molybdenum alloys
Polarization
Prosthetics
Anisotropic response
Corrosion behavior
Corrosion property
Orientation dependent
Polarization curves
Post heat-treatment
Prosthetic devices
Selective laser melting (SLM)
Selective laser melting